Antenna director



March 14, 1961 WELLS 2,975,423

ANTENNA DIRECTOR Filed March 24, 1958 F/QZ f F/G./

DON/1L0 H. WELLS INVENTOR 5y M1 TH A T TORNE Y s e a it States Patent-OANTENNA DIRECTOR Donald H. Wells, Burlington, Iowa, assignor to AntennaDesigns, Inc., Burlington, Iowa, a corporation of Iowa Filed Mar. 24,1958, Ser. No. 723,181

8 Claims. (Cl. 343-833) This invention relates to antennas and moreparticularly to a director used in an antenna system which will functioneffectively over a wide range of frequencies.

The television antenna art has developed a Yagi type antenna systemwhich is designed to receive signals that vary over several bands offrequencies. These bands are in the very high frequency range, the lowband which range from 54 to 88 megacycles and the high band which rangesfrom 174 to 216 megacycles, and in the ultra high frequency range a bandfrom 470 to 890 megacycles. 'The Yagi type antenna system produces again by placing several parasitic elements in alignment with the drivenelement. The parasitic elements that are so placed'between the drivenelement and the source of the signal are called directors and the othersare called refiectors. The electrical properties of known directors aresuch that they will give a gain for one of the bands, but very little orno gain for the other bands.

It is therefore an object of this invention to provide a director usedin an antenna system that will give a substantial gain for both the lowband and the high band of frequencies in the very high frequency rangeand the ultra high frequency band used in television broadcasting.

Another object of this invention is to provide a director used in anantenna system that will give a substantial gain over a wide range offrequencies.

Another object of this invention is to provide a director used in anantenna system that will function effectively over a wide range offrequencies and is simple and inexpensive to construct.

Further objects and advantages of this invention will become morereadily apparent from the following drawings, descriptions and claims.

In the drawings Fig. l is a view of the director and Fig. 2 is a view ofan antenna system using the director. The director 1 is composed of twosections 2 and 3 which are connected at their ends by a quarter Wavelength stub 4 for near the ultra high frequency range. A quarter wavelength stub 5 for near the high end of the high band in the very highfrequency range is connected near the middle of section 2. Anotherquarter wave length stub 6 for near the high end of the high band in thevery high frequency range is connected near the middle of section 3. Thequarter wave length stubs 4, 5 and 6 may be positioned on the sections 2and 3 so as to be substantially in a single plane. The open ends of thequarter wave length stubs 5 and 6 are held in position near the quarterwave length stub 4 by the insulators 7 and 8 which are fastened to thesections 2 and 3.

One type of antenna system in which the director 1 may be used is shownin Fig. 2. The antenna system is composed of a low band half wave lengthdipole driven element 9, a high band full wave length dipole drivenelement 10, an ultra high frequency band half wave length dipole drivenelement 11, two high band directors 12 and 13 and the director 1. Thedipole driven elements 9, 10 and 11 and the directors 1, 12 and 13 areheld in position in a single plane by a supporting rod 14.

i and the very high frequency stubs is not critical.

2,975,423 Patented Mar. 14, 1961- The dipole driven elements 9, 10 and11 are connected by conductors 15. A transmission line 16 is connectedto the conductors 15.

The electrical properties of the director 1 are such that it will givegood gain to the antenna system in the low band, the high band and theultra high frequency band. The electrical properties of the quarter wavelength stubs 5 and 6 are such as to make the sections 2 and 3 of thedirector 1 effectively disconnected half wave length high band directorsfor the high end of the high band. The quarter wave length stubs 5 and 6have little or no efiect at the low end of the high band. Therefore thequarter wave length stub 4 is inserted between the sections 2 and 3 ofthe director 1 to improve the phasing of the sections 2 and 3 of thedirector 1 at the low end ofthe high band. The quarter wave length stub4 also has the effect of making the two sections 2 and 3 of the director1 appear to be a single half wave length director for the low band. Thequarter wave length stub 4 and the quarter wave length stubs 5 and 6have the effect of.

ultra high frequency band, the over all length of the di-.

rector 1 is increased over that possible if the quarter wave length stub4 would be for the very high frequency bands.

The director 1 may be used in many antenna systems having differenttypes of driven elements and having other directors and reflectors. Itcan be readily seen that the director may be used with driven elementsof the folded dipole type of other types. No reflectors are shown butthey may be added to the antenna system with-' out imparing theeffectiveness of the director 1. The plane of the positioning of theultra high frequency stub The director 1 may be also used as a drivenelement as Well as a director.

I claim:

1. An antenna system comprising an ultra high frequency band drivenelement, a very high frequency high band driven element, a very highfrequency low band driven element and a parasitic element so arranged asto be a director and comprising two half wave length high band sectionsconnected together at one end of each section by an ultra high frequencyquarter wave length stub, a very high frequency quarter wave length stubcon-j nected at its closed end to one of the two sections and anothervery high frequency quarter wave length stub connected at its closed endto the other of the two sections.

2. An antenna system comprising an ultra high frequency band drivenelement, a very high frequency high band driven element, a very highfrequency low band driven element and a parasitic element so arranged asto be a director and comprising two half wave length high band sectionsconnected together at one end of each section by an ultra high frequencyquarter wave length stub, a very high frequency quarter wave length stubconnected at its closed end to one of the two half wave length high bandsections and having its open end positioned near the ultra highfrequency quarter wave length stub, another very high frequency quarterwave length stub connected at its closed end to the other of the twohalf wave length high band sections and having its open end positionednear the ultra high frequency be a director and comprising "two halfwave length high band sections connected together at one end of eachsection by an ultra high frequency quarter wave length stub, a very highfrequency quarter wavelength stub connected at its closed end to nearthe "ir'iiddle of one of the two half wave length high band sections andhaving its open end positioned near the ultra high frequency quarterwave length stub, another very high frequency quarter wave length s't'uoconnected at its closed end to near the middle of the other of the twohalf wave length high band sections and having its open end positionednear the ultra high frequency quarter wave length stub.

4. An antenna system comprising an ultra, high frequency band drivenelement, a veryfhigh frequency high band driven element, a very highfrequency low 'b'and driven element and a parasiticelerne'r'itsoarranged as to be a director and comprising two half wave length highband sections connected together at one "end of each section by anultrahigh frequency quarter wave length stub, a quarter wave length stubfor the high end of the high band in the very high frequency rangeconnected at its closed end to near the middle of one of the two halfwave length high band sections and having its open end positioned nearthe ultra high frequency quarter wave length stub, another quarter wavelength stub for the high end of the high band in the very high frequencyrange connected at its closed end to near the middle of the otherof thetwo half wavelength high band sections andh'aving its open endpositionednear the ultra high frequency quarter wave length stub.

5. An antenna system comprising a very high frequency high band drivenelement, a very high frequency low band driven element and a parasiticelement so arranged as to be a director and comprising two half Wavelength high 'band sections connected together at one end of each sectionby an ultra high frequency quarter wave lengthstub, 'a very highfrequency quarter wave length stub connected at its closed end to one ofthe two half wave length high band sections and having its open endpositioned near the ultra high frequency quarter wave length stub,another very high frequency quarter wave length stub connected at itsclosed end to'the other of the two half'wave length high band sectionsand having itsopen end positioned near the ultra high frequency quarterwave length stub. I

6. An antenna "system comprising a very high frequency high band drivenelement, a very high frequency low band driven element and a parasiticelement so arranged as to be a director and comprising two half wavelength high band sections connected together at one endof each sectionby an ultra high frequency quarter wave length stub, a very highfrequency quarter wave length stub connected at its closed end to nearthe middle of one of the two half wave length high band sections andhaving its open end positioned near the ultra high frequency quarterwave length stub, another very high frequency quarter wave length stubconnected at its closed end to near the middle of the other of the twohalf wavelength high band sections and having its open end positionednear the ultra high frequency quarter wave length stub.

7. An antenna system comprising a very high frequency high band drivenelement, a very high frequency low band driven element and a parasiticelement so arranged as to be a director and comprising two half wavelength high band sections connected together at one end of each sectionbyan ultra high frequency quarter wave length stub, a quarter wavelength stub for the high end of the high band in the very high frequencyrange connected at its closed end to near the middle of one of the twohalf wave length high band sections and having its open end positionednear the ultra high frequency quarter wave length stub, another quarterwave length stub for the high end of the high band in the very highfrequency range connected at its closed end to near the middle of theother of the two half wave length high band sections and having its openend positioned near the ultra high frequency quarter wave length stub.

8. An antenna system comprising a very high frequency high'band drivenelement, avery high frequency low band driven element and a parasiticelement so arranged as to be a director and comprising two half wavelength high band sections connected together at one end of each section'by an ultra high frequency quarter wave length stub, a very highfrequency quarter 'wave length stub connected at its closed end to oneof the two sections and another very high frequency quarter wave lengthstub connected at its closed end to the'other of the two sections.

ReferencesCited in 'the'file of this patent

